package com.qunar.im.ui.view.progress.glide;


import okhttp3.MediaType;
import okhttp3.ResponseBody;
import okio.*;

import java.io.IOException;

/**
 * @author  "https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/Progress.java"
 * @see <a href="https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/Progress.java">OkHttp sample</a>
 */
class ProgressResponseBody extends ResponseBody {

    private final ResponseBody responseBody;
    private final ProgressListener glideProgressListener;
    private BufferedSource bufferedSource;

    public ProgressResponseBody(ResponseBody responseBody, ProgressListener glideProgressListener) {
        this.responseBody = responseBody;
        this.glideProgressListener = glideProgressListener;
    }

    @Override
    public MediaType contentType() {
        return responseBody.contentType();
    }

    @Override
    public long contentLength() {
        return responseBody.contentLength();
    }

    @Override
    public BufferedSource source() {
        if (bufferedSource == null) {
            bufferedSource = Okio.buffer(source(responseBody.source()));
        }
        return bufferedSource;
    }

    private Source source(Source source) {
        return new ForwardingSource(source) {
            long totalBytesRead = 0L;

            @Override
            public long read(Buffer sink, long byteCount) throws IOException {
                long bytesRead = super.read(sink, byteCount);
                // read() returns the number of bytes read, or -1 if this source is exhausted.
                totalBytesRead += bytesRead != -1 ? bytesRead : 0;
                glideProgressListener.update(totalBytesRead, responseBody.contentLength(), bytesRead == -1);
                return bytesRead;
            }
        };
    }
}
